I'm new to this game so if everybody knows this just ignore me, but I haven't found it in any of the strategy guides I've read. It looks like the wand of cloudkill ignores magic resistance. I was having trouble with the second room of the mind flayer lair in the sewers, so I tried having my mage open the door, use the wand, then close it. Lo and behold, all of the flayers were damamged every round without MR stopping it. I happened to have a cloudkill spell memorized as well, so I reloaded and tried the spell, but this time their MR worked and kept them from being damaged most of the time. I tried my wand of fireballs, but they got MR against that as normal, too. Is anybody else aware of this? Am I missing some obvious reason why this shouldn't work? Does it work for any other wands or spell casting items? (I know about the ring of the ram). Regardless, since stores provide the same "wand-recharging service" they did in BG1, I think my game just got a whole lot easier.

Also, while we're on the topic of MR ignoring items, does anyone happen to know if the ring of energy (sold by Ribald) ignores MR like the ring of the ram does? I haven't had a chance to check it out.

Ring of energy should ignore MR, but it doesn't. I had a hard time hurting those Clay golems, since I didn't had any blunt weapons, except my mage's quarterstaff (which I borrowed to Minsc).
Cloudkill should ignore MR also, because there is nothing magical in air that you're breathing (which Cloudkill is).

OK, but then why is it only the wand that ignores MR and not the spell?

A Baldurdash fixpack has fixed Cloudkill from wands bypassing magic resistance. The vapours are magical in nature so magic resistance should apply. This does mean that you can no longer lock shut mind flayers in a room with a Cloudkill for company, but so it goes. You can still kill their umber hulk pets, though.

Yes, you close the door, and those soooo intelligent mind flayers just don't think they can open it! Looks like a game limitation, so this trick shouldn't be played with THEM at least... (Trolls, it's different)

Mind flayers are retarded without tactics fix (wait a minute do they even have one?). They try to eat the brains of skeletons... who already have no brains, and 0 intelligence.